Preliminary study of airborne particulate matter in a Beijing sampling station by instrumental neutron activation analysis

A long-term study on airborne particulate matter (APM) and air pollution trend in Beijing has been undertaken supported by International Atomic Energy Agency (IAEA) and National Natural Science Foundation of China. Sampling was carried out using Gent stacked filter unit sampler at a sampling station (traffic representative) in Beijing city. Two hundred and ten samples were collected during 1999 and 2000 in two size fractions of PM10 (coarse) and PM2.5 (fine). About 45 elements were determined for most of the samples by instrumental neutron activation analysis. Enrichment factor analysis and Factor Analysis were performed based on data determined. Possible sources of the APM were preliminarily identified. Some interesting correlation was observed between sandstorm episode and the variation of relevant element concentrations. In general, during the sandstorm episodes the concentrations of crust elements with natural origin increase dramatically and the increase of fine fraction is usually higher than that of coarse fraction. On the contrary, the pollution elements of local origin decrease during sandstorm episodes.